A 2-yr study using Mashona- (M, yr 1 and 2) and Tuli-sired (T, yr 2) cows produced from a three-breed diallele cow base comprised of Brahman (BB), Romosinuano (RR), and Angus (AA) was conducted to determine effects of breed type and growing strategies on growth performance and carcass characteristics in early-weaned calves. Steers and heifers used were between 90 and 200 d old at arrival. Cattle were randomly split into one of two nutritional treatment groups with sex, breed type, and age stratified across treatments. Calves were either fed a roughage diet (P) or placed immediately on a concentrate grower diet (F) for approximately x d, then finished together in the feedlot. In both years, F calves gained more (P < .01) than P calves during the growing stage. In yr 1, P calves gained more (P < .05) than F calves during the middle, late and overall finishing period. For yr 2, F calves gained more (P < .05) during the early finishing phase, but P cattle gained more (P < .05) during the middle portion. In yr 1, P calves had higher (P < .05) USDA marbling scores than F calves. Growing program had no effect on carcass characteristics during yr 2. In yr 1, MAA calves gained more (P < .05) during the overall finishing period. TAA calves gained more (P < .01) during the growing stage and TBB calves gained more (P < .05) for the overall finishing period in yr 2. In yr 1, MAA and MBB were fatter (P < .05), and MAA and MAR calves deposited more (P < .01) marbling than others. MAA calves also had less (P < .05) desirable yield grades than other cattle. In yr 2, TAA calves had more (P < .05) marbling than other calves, followed by TRR cattle that deposited more (P < .05) than remaining calves.
- Sawyer, Jason Associate Professor and Associate Department Head